P1580: MANAGEMENT OF PATIENTS WITH MASTOCYTOSIS DURING THE COVID-19 PANDEMIC: A SINGLE CENTER EXPERIENCE
Authors: V. Filipponi, G. Palumbo, M. Ribersani, M. L. Moleti, A. Angi, M. C. Molinari, R. Maglione, F. Giona
Journal: HemaSphere (2022)

Background: The risk of developing severe symptoms caused by SARS-CoV2 infection in patients (pts) with cutaneous mastocytosis (CM), or indolent systemic mastocytosis (ISM) is like that of healthy people. Unfortunately, the risk may increase in pts with aggressive systemic mastocytosis (ASM), or mastocytosis associated to a hematologic neoplasm (SM-AHN). SARS-CoV2 vaccination reduces the risk of a potentially fatal infection. Considering the increased risk of allergic reactions, it is crucial for these pts to be safely vaccinated. The incidence of vaccine-related anaphylaxis has been reported to be 5 times higher for mRNA vaccines than others. The Italian Ministry of Health (MH) suggests mRNA vaccines for frail individuals. In pts with mastocytosis, it recommended prophylaxis with antihistamines from the day prior to the vaccination to 5 days after, and an observation of 60 min after the vaccination. The administration of the vaccine in a hospital setting was recommended in those with a history of anaphylaxis episodes. In our hospital a vaccination campaign for frail pts in 2 phases was organized. Aims: The aim of this study is to retrospectively evaluate the incidences of SARS-CoV2 infection in our pts with mastocytosis, the complications that may arise, incidence and type of vaccination, and the frequency of adverse reactions to vaccines. Methods: Sixty-three pts with mastocytosis, 30 adults (14 male, 16 female; median age 57.1 years) and 33 children (17 male, 16 female; median age 4.7 years, 2 of them >16 years) were considered. According to the WHO 2016 classification, out of 30 adults, 5 had isolated CM, 15 ISM, 1 had smouldering mastocytosis (SSM), 5 had ASM, and 4 SM-AHN. Out of 33 pediatric pts, 1 had ISM, 18 maculopapular cutaneous mastocytosis, 8 diffuse cutaneous mastocytosis and 6 mastocytoma. Seven adults had a history of anaphylaxis. Results: Overall, 5 adult pts (3 ISM, 2 ASM), and none of the pediatric pts, got SARS-CoV2 infection (Table 1). Four of them refused vaccination when it became available. Out of 8 frail mastocytosis pts (4 ASM, 4 SM-AHN) without previous SARS-CoV2 infection, 4 (2 ASM, 2 SM-AHN), in treatment with kinase inhibitors (KI), accepted it, and 4 refused. Overall, 21/32 pts (65%) eligible to have the SARS-CoV2 vaccination received it. Fifteen out of 21 pts (1 CM, 6 ISM, 1 SSM, 4 SM-AHN, 3 ASM) received the mRNA vaccine according to the Italian MH recommendations, 5 at our hospital, and 10 elsewhere. Patients were treated with cetirizine 10 mg twice a day as antihistamine prophylaxis. Out of these 15 pts, 4 had previous episodes of anaphylaxis, and 5 (3ASM, 2 SM-AHN) were in treatment with KI (2 Imatinib, 3 Midostaurin). The remaining 6 pts (2 CM, 3 ISM, 1 ASM) received vaccination (5 mRNA and 1 viral vector vaccine) without any prophylaxis and/or caution. One of these patients had had previous episodes of anaphylaxis. Both doses of vaccine were well tolerated in all pts. None showed adverse events, anaphylactic vaccine-related reactions, or developed COVID-19 infection after vaccination. Image:Summary/Conclusion: In our experience, 35% of pts with mastocytosis eligible to receive the SARS-CoV2 vaccination, refused it. This is in line with the general population. None of the vaccinated pts had adverse events or anaphylaxes, regardless of prophylaxis and type of vaccine. None of the pts that received vaccination developed SARS-CoV2 infection. Pts affected by SARS-CoV2 infection (8%) completely recovered, including those with an advanced form of mastocytosis in treatment with KI.